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Tuberculosis drugs and their side effects

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Introduction

Treatment for tuberculosis (TB) typically involves a six month course of antibiotics. Antibiotics kill bacteria.

TB is a serious condition, but in most cases it can be cured with the right treatment.

If you have active TB affecting the lungs (pulmonary TB) you will be contagious up to three weeks into treatment. Active TB causes symptoms and can be spread to others. Latent TB cannot be spread to others and does not cause any symptoms. Latent TB can develop into active TB.

The four main antibiotics used to treat TB are:

  • isoniazid
  • rifampicin
  • ethambutol
  • pyrazinamide

It is important to take these medications exactly as you are told to by your doctor. Contact your doctor if you miss a dose or have any concerns about your medication.If you take too high a dose, seek emergency medical help straight away.

Allergies and Reactions

It is possible to have an unwanted reaction to antibiotics.

Seek emergency medical attention if you experience any signs of an allergic reaction, including:

Seek emergency medical attention if you experience a severe skin reaction. Possible symptoms may include:

  • a high temperature (fever)
  • a sore throat
  • a burning sensation in your eyes
  • painful skin
  • a red or purple skin rash that spreads and causes blistering and peeling

Get emergency medical help if you experience any of the symptoms of a serious drug reaction, including:

A drug reaction can affect many parts of the body and may occur several weeks after you begin using these antibiotics.

Ethambutol

Ethambutol is one of the medications used to treat TB. It is usually prescribed during the first two months of treatment.See your doctor straight away if you develop any problems with your eyesight.

What to know before taking ethambutol

Your doctor may sometimes give you a blood test while you are taking ethambutol to check that the correct amount of medication is in your system.Before taking ethambutol, it is important you tell your doctor if you:

  • are pregnant or breastfeeding
  • have any problems with your eyesight
  • have a history of kidney problems
  • are taking any other medicines, including prescription and non-prescription drugs, and herbal remedies
  • are allergic to any medications
  • any other medical problems

There is no evidence that ethambutol causes harm during pregnancy, but it is important that you tell your doctor regardless.

Side effects of ethambutol

Ethambutol can cause:

  • eyesight problems (colour blindness, blurred vision, poor vision, partial loss of vision)
  • joint problems
  • nerve disorders
  • kidney problems

Seek immediate medical attention if you experience any of these symptoms.This is not a full list of possible side-effects. See you doctor if you experience any symptoms you feel may be caused by this medication.

Isoniazid

Isoniazid is an antibiotic that can be used to treat active TB and prevent latent TB from becoming active.When isoniazid is used to treat active TB, it is usually prescribed in combination with other medicines.

What to know before taking isoniazid

You might be given supplements of vitamin B6 (pyridoxine) to take alongside isoniazid to prevent nerve damage (peripheral neuropathy).

Isoniazid can cause liver problems on rare occasions. Your doctor may test your liver function before you start treatment to make sure you can take the medication safely and you may continue to be tested each month while you are taking isoniazid.

You should avoid drinking alcohol when taking isoniazid as it can increase your risk of liver damage.

You should also avoid any foods that are high in tyramine or histamine, including:

  • beer or wine (especially red wine)
  • cheese (especially mature, aged or processed cheeses)
  • fermented soy products (soya sauce, miso soup)
  • fermented yeast products (e.g. Bovril®, Oxo® or Marmite®)
  • fava beans
  • pickled foods
  • smoked fish, herring, tuna, skipjack or other tropical fish
  • cured salami and sausages

Check with your doctor if you are unsure about eating any foods.

Call your doctor immediately if you experience:

  • persistent nausea (feeling sick)
  • suddenly feeling weak or ill, or fever lasting 3 days or more
  • pain in your upper stomach (which may spread to your back)
  • loss of appetite
  • dark urine or clay-colored stools
  • vision changes or pain behind your eyes
  • confusion, memory problems or unusual thoughts or behaviour
  • a fit (seizure)
  • pale skin, easy bruising or bleeding (including nosebleeds or bleeding gums)
  • jaundice

This is not a full list of possible side-effects and you should always contact your doctor if you are worried about your health while taking this medication. More potential side-effects are listed below.

You are at a higher risk of liver problems from isoniazid if you:

  • are aged between 35 and 65
  • are a woman, especially if you are of Hispanic or African American ancestry or have just given birth

Isoniazid is not suitable for people with certain conditions, and should only be given to some individuals with caution.Before taking isoniazid, you should tell your doctor if you:

  • have a history of liver disease
  • suffer from kidney disease
  • suffer from chronic renal failure
  • suffer from psychosis
  • have nerve problems that cause pain, weakness, or numbness
  • have epilepsy or diabetes
  • have HIV or AIDS
  • drink large amounts of alcohol
  • are malnourished
  • have a rare blood condition called porphyria
  • are taking any prescription or non-prescription medications, including herbal remedies
  • have ever had an allergy to a medicine
  • have any other medical conditions

This will help your doctor decide if this medication is safe for you to take.

You should also tell your doctor if you are pregnant or trying for a baby. Isoniazid is not known to cause harm in pregnancy, but your doctor may need to provide you with a vitamin supplement.

Side effects of isoniazid

Common side effects of taking isoniazid may include:

If you experience any numbness or tingling, let your doctor know as soon as possible.See your doctor if you have the following symptoms:

  • fever
  • skin rash
  • hearing problems
  • mood changes
  • difficulty passing urine

Isoniazid can sometimes cause liver problems. Seek immediate medical attention if you experience any of the following symptoms:

  • nausea or vomiting
  • upper stomach pain (which may spread to your back)
  • feeling very weak or tired
  • loss of appetite
  • jaundice

Visit a doctor or pharmacist if you are worried about any other symptoms that you suspect have been caused by this medicine.

Pyrazinamide

Pyrazinamide is also known as zinamide.

Pyrazinamide is an antibiotic which can sometimes cause liver problems. Your doctor may occasionally want to take blood tests during treatment to make sure your liver is functioning properly.

Pyrazinamide can be taken in combination with other medications to treat TB. Pyrazinamide is typically taken during the first two months of treatment.

What to know before taking pyrazinamide

Your liver may need to be checked regularly while you are taking pyrazinamide to make sure it is functioning properly.

Before taking pyrazinamide, it is important that you tell your doctor if you:

  • are pregnant or breastfeeding
  • have a history of kidney problems
  • have a history of liver problems
  • have gout or diabetes
  • drink a lot of alcohol
  • have the rare inherited blood disorder porphyria
  • are taking any other medicines, including prescription and non-prescription drugs, and herbal remedies
  • if you have ever had an allergic reaction to a medicine
  • any other medical problems

Pyrazinamide can stop the oral typhoid vaccine from working, so if you are having any vaccinations, make sure you tell the person in charge of your treatment that you are taking pyrazinamide.

Side effects of pyrazinamide

Stop taking pyrazinamide and get emergency medical help immediately if you experience any of the following symptoms:

This is not a full list of all possible side-effects. See your doctor if you experience any other symptoms that you think might be caused by this medication.

Rifampicin

Rifampicin is an antibiotic that is used to treat serious infections, including TB. When prescribed for TB, it is usually one of a number of medicines used to treat the infection.

It can be used to protect you from a TB infection if you have been in close, prolonged contact with an infected person.

What to know before taking rifampicin

Your doctor may want to take blood tests every now and again while you are taking rifampicin to make sure your liver is working properly.

Rifampicin can react with other medications, so make sure you tell your doctor if you are taking any prescription or non-prescription drugs or any herbal remedies.

Rifampicin can reduce the effectiveness of some types of contraception, like the combined contraceptive pill. You should use an alternative method of contraception during treatment, like condoms.

Before you start taking rifampicin, it is important that you tell your doctor if you:

  • are pregnant or breastfeeding
  • have a history or liver problems
  • have a history of kidney problems
  • have jaundice
  • have a rare inherited blood disorder called porphyria
  • are taking any other medicines (including prescription drugs, non-prescription drugs, and herbal remedies)
  • are allergic to any medications
  • any other medical problems
  • gout
  • diabetes

Side effects of rifampicin

Rifampicin can cause your urine, tears, saliva and sweat to have an orange or reddish colour, but this is nothing to worry about. You can avoid wearing soft contact lenses while taking this drug as they can become permanently stained.

Other common side effects include:

If your diarrhoea persists for more than 24 hours, becomes severe or is bloody, seek medical attention immediately.

To help with a headache, drink plenty of water and ask your pharmacist to recommend a painkiller. Visit your doctor if the headache continues.

See your doctor if you experience any of the following flu-like symptoms:

  • a fever, chills
  • feeling short of breath, wheezing or trouble breathing
  • flushing
  • skin rashes
  • itching
  • feeling tired
  • dizziness

See your doctor immediately if you experience any symptoms of early liver damage, including:

  • nausea or vomiting
  • upper stomach pain (which may spread to your back)
  • sudden weakness or tiredness
  • loss of appetite
  • jaundice

This is not a full list of all possible side-effects. See your doctor if you experience any other symptoms that you think might be caused by this medication.

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Next review:
23 January 2023

Important: Our website provides useful information but is not a substitute for medical advice. You should always seek the advice of your doctor when making decisions about your health.